Bark-removing machine having cutters yieldably mounted for riding-over obstacles



July 31, 1956 B. VALO 2,756,786

BARK-REMOVING MACHINE HAVING CUTTERS YIELDABLY MOUNTED FOR RIDING-OVEROBSTACLES Filed Dec. 4, 1952 2 Sheets-Sheet 1 IN V EN TOR.

.B. Valo,

W, {M a. Zak/wk ATTYJ,

July 31, 1956 B. VALO BARK-REMOVING MACHINE HAVING CUTTERS YIELDABLYMOUNTED FOR RIDING-OVER OBSTACLES 2 Sheets-Sheet 2 Filed Dec. 4, 1952INVENTOR. B. Valo, BY

ATTYJ.

United States Patent O BARK-REMOVING MACHINE HAVING CUTTERS YIELDAgLYMOUNTED FOR RIDING-OVER B- STACLE The invention relates to a device forremoving bark from logs.

Machines of this kind are known in which the logs to be peeled arecarried in longitudinal direction by endless conveyors through one orseveral sets of stationary cutters, which are arranged circumferentiallyaround the log and in a shaving-like manner peel the bark from themoving log surface. The cutters are according to known proposals mountedin arms which are turnable around one single bearing point.

The drawback of said known arrangements is that a cutter, mounted in anarm which is only turnable around one single bearing point will never beable to yield or give way sufficiently if the cutter encounters a hardobstacle, such as a branch. Such cutters will therefore always run therisk of jamming in the harder parts of the log surface. As a matter offact the problem how to build cutters by which the risk of either beingdemolished or jammed when encountering hard obstacles is not hithertosolved.

The object of the present invention is the provision of a machine of theinitially described character wherein the supports for the cutters areset in a unique and new manner so as to eliminate said disadvantages.

The main object of the invention is thus to arrange the cutters of themachine in such a way that they, when encountering a hard obstacle willsimultaneously yield in the longitudinal direction of log travel andradially outward from the log surface.

Another feature of the arrangement is that the angle between the cuttingedge and the log surface is always maintained constant irrespective ofthe yielding movements of the cutter.

Still another feature of the invention is the shape of the cutterscutting edge, this being ground to form two surfaces at substantiallyright angles to each other, one surface being parallel to and abuttingthe log surface while the other surface is positioned at right anglesthereto.

With these and other objects in view the invention consists in thefeatures of construction as will be hereinafter more fully described indetail with reference to the accompanying drawing, whichdiagrammatically shows preferred embodiments of the arrangement.

In the drawing:

Fig. 1 is an end view of the machine showing the cutting elementsarranged circumferentially around the log, the end of which is shown inthe center of the figure.

Fig. 2 is a fragmentary vertical section as indicated by the line 22 inFig. 1, and shows one of the cutters and part of the cutter support inside elevation.

Fig. 3 is a vertical section of another arrangement of the cuttersupport according to the invention.

Similar reference characters indicate corresponding parts throughout theseveral figures in the drawing.

Referring to Fig. 1 the machine comprises a support arrangement for tencutters 1, each of which is pivotally mounted between a pair of spacedflanges 4a of an annular support plate 4, having a hole 7 through whichthe log to be peeled is moved. A pair of spaced links or arms 2 arePatented July 31, 1956 pivoted at one end about parallel axes to each ofthe flanges 4a by pins band b and the cutter 1 is pivoted about parallelaxes to the other end of opposed pairs of the arms 2 by pins (2 and a,the pivot axes of the pins b and b also extending parallel to the pivotaxes of the pins 11 and a. The cutting edge of the cutter is ground soas to have one surface 5 extending perpendicularly to the surface of thelog and another surface abutting the log surface and being situatedparallel to it. Said arrangement of the cutting edge of the cutter isimportant for preventing the cutter from jamming into the log surface,which unavoidably would occur if the angle between the cutter surface 5and the unpeeled part of the log surface would be greater than a rightangle.

The cutters 1 are pressed against the log surface by means of resilientpressing devices such as springs 6. If the cutter when the log iscarried by its conveyor through the central hole 7 in the support plate4 in the direction indicated by the arrow encounters a hard obstacle inthe log surface the cutter will yield and will be shifted by a swingingmovement relative to the pivot pins a, a and b, b to some position suchas that shown in phantom outline in Fig. 2. During this movement thecutter travels backwards in the direction of the arrow A as well as awayfrom the log surface. On account of the provision of the two paralleland equal arms 2 the angle between the edges of the cutter 1 and thesurface of the log will always remain constant, since such angle doesnot vary with the swinging movement or position of the cutter.

According to Fig. 3 the cutters 11 are arranged to move according to thesame rule as in the foregoing figures, the difference being, however,that no support arms for the cutters are provided. Instead thereof thecarrier plate 14 is provided with guiding grooves 20 situated in aninclined position relative the surface of the log and in which groovesthe cutters 11 are arranged in the same inclined position as is shown inFigures 1 and 2. Even in the embodiment of the invention according toFig. 3 pressing means, such a-s springs 6' are provided for pressing thecutter against the log surface. The device works also substantially inthe same manner as the aforedescribed embodiment of the device. If thelog, which is moved through the hole 17 in the stationary support frame14 comprises hard obstacles in the surface, the cutter 11 will bepressed longitudinally into the guiding groove 20, the result being thatthe cutter edge becomes displaced as well backwards as upwards from thelog, the angle between the edge and the log, however, remainingunchanged.

The position of the front surface 5 of the cutter is of great importancefor the self-adjusting operation of the cutters. If for instance a thicklog is following after a thin one through the cutter support hole 7 or17 the cutter front edge 5 will hit against the log end surface. Whilsta sharp or inclined cutter edge now would cut into the log end andfasten there, this does not happen with the cutter according to theinvention. This cutter will simply be pushed backwards and due to itssimultaneous radially outward movement the front surface 5 will glideoff the log end and ride onto the softer bark layer and commence thepeeling operation at the right place.

While the preferred embodiments of the instant invention has beenillustrated and described it will be understood it is not intended tolimit the scope of the invention thereto, as many minor changes indetail of construction may be resorted to.

What I claim is:

1. A self-adjusting log peeler comprising a support, at least oneelongate cutter element for removing bark from a log moving axially andrelatively thereto, said cutter element being mounted in said supportfor movement to ward and away from the surface of a log being debarked,and said cutter element being mounted so that its longitudinal axis,when considered from an outer end of the cutter element toward thecutting end, overlies a bark-free portion of such log being debarked andinclines toward an unbarked portion of such log, said longitudinal axisof the cutter element, during said movement of the cutter elementmaintaining a substantially constant angle of inclination to alongitudinal axis of a log being debarked, and resilient means urgingsaid cutter towards such log whereby the cutter element, whenencountering a hard obstacle, can overcome the effect of said resilientmeans and ride over such obstacle.

2. A log peeler as described in claim 1 in which the peeling edge of thecutter element is ground to form a substantially right angle of whichone side is parallel to an abutting log surface and the other side islocated vertically thereto.

3. A log peelcr as described in claim 1, in which said cutter element isslidably mounted in a guiding groove provided in said support, saidguiding groove having the same inclination as said longitudinal axis ofthe cutter element, and in which said resilient means comprises aspring.

4. A log peeler as described in claim 3 in which the peeling edge of thecutter element is ground to form a substantially right angle of whichone surface is parallel to an abutting log surface and the other surfaceis located vertically thereto.

5. A log peeler as described in claim 1, said support comprising anannular frame having a central hole through which a log is moved, aplurality of flanges on said support, and there being a plurality ofcutter elements mounted on said flanges, each cuttenelement beingpivoted to at least two parallel arms on two transverse axes spacedalong said longitudinal axis of the cutter element, and said twoparallei arms being swingablymounted on their associated flange.

6. A log peeler as described in claim 5 in which the peeling edge ofeach of the cutter elements is ground to form a substantially rightangle of which one surface is paraliel to an abutting log surface andthe other surface is located vertically thereto.

References Cited in the file of this patent UNITED STATES PATENTS1,440,042 Whalley Dec. 26, 1922 1,539,603 Saprones May 26, 19252,452,631 Cameron Nov. 26, 1948

